       (->>
         {:data/type data-type
          ::height height
-         ::keys (vec (drop 1 child-keys))
+         ::keys (vec (rest child-keys))
          ::children new-children
          ::record/count record-count
          ::record/first-key (first child-keys)

  "Rewrite a vector of childen into numbered links."
  [children]
  (into []
        (map-indexed
          #(mdag/link
             (format "%03d" %1)
             (if (mdag/link? %2) %2 (meta %2))))
        children))



    (if (<= (count layer) 1)
      (first layer)
      (let [index-groups (part/partition-limited
                           (::branching-factor params default-branching-factor)
                           layer)]
        (recur (mapv (partial store-index! store height) index-groups)
               (inc height))))))
